I have been using a mega 2560 from an old IBM T30 laptop - with no real problems. There were a few problems recently with up loading, so I decided to re-install the 2560 - to see if that would resolve the issues.
Despite using exactly the same method to install the driver (Windows CDC / USB driver) using the .inf on the Arduino website, it refuses to install again. I get the option to pick the 2560, accept the whql warning, but then it stops - with a simple "the installation has detected an error" - " the data is not valid" (!). I have investigated the script, and been through all sorts of checks on registry permissions. To no avail. How on earth do I get to use my 2560 again? (I've checked another machine - no problem- but I want to program from the laptop!!) Anybody seen this kind of error? thanks, Graeme